Launch and Recovery Systems (LARS) are the integrated handling packages that move valuable payloads between a vessel’s deck and the sea. Combining a lifting structure, winch, control system, and safety devices, they protect three things at once: the payload, the vessel, and the crew. When a subsea vehicle can cost millions of dollars, controlling how it crosses the water’s surface is not optional.
This article explains how a LARS works, from pre-launch checks and outboard transfer to lowering through the splash zone, release, and recovery. It then surveys the main system types, including A-frames, davits, cranes, cursor systems, active heave compensated units, and containerized designs, along with the core components that make up each one.
It also covers where these systems are used, from offshore oil and gas and wind farms to defense, scientific research, and search and rescue. The benefits are weighed against real limitations such as harsh sea states, snap loads, maintenance demands, and operator skill.
Finally, the article offers a practical framework for choosing the right system, covering payload, operating conditions, vessel constraints, certification, support, and lifecycle cost. It closes with an overview of Reel Power Marine & Energy’s LARS range, built to help offshore teams work safely and keep projects on schedule.
What is a Launch and Recovery System (LARS)?
A Launch and Recovery System is a purpose-built handling package that moves payloads between a vessel’s deck and the sea. It combines a lifting structure, a winch, a control system, and safety devices into one integrated unit.
The system exists to protect three things: the payload, the vessel, and the crew. A subsea vehicle can cost millions of dollars or more, and a poor launch can damage it in seconds. A controlled system removes most of that risk.
You may also hear related terms such as Launch and Recovery Equipment (LARE), A-frame, davit, or handling system. In practice, these describe the same function or one part of it. In defense and naval settings, the term often applies to systems that deploy unmanned surface vessels, rigid-hulled inflatable boats (RHIBs), and mine countermeasure assets.
How Does a Launch and Recovery System Work?
A LARS follows a clear sequence of lift, transfer, lower, and release. Each stage is built to control the motion that waves and vessel movement create. The goal is simple: move a payload between deck and water without letting the sea decide how it travels.
1. Pre-launch Checks and Lifting the Payload on Deck
The operator inspects lifting points, umbilical connections, latches, and deck clearances before anything moves. Then the winch or crane raises the payload from its stowed position. A short, disciplined check at this stage prevents most failures later in the cycle.
2. Moving the Payload Outboard
An A-frame, davit, or crane arm swings or slides the payload past the vessel’s side or stern. This keeps it clear of the hull, thrusters, and propellers. Deck crew often use tag lines or guide systems to stop the load from swinging while it travels over the rail.
3. Lowering Through the Splash Zone
The splash zone is the layer of water near the surface where waves break and the vessel pitches and rolls. It is the most dangerous part of the operation. Waves can slam the payload against the hull, and sudden vessel movement can create snap loads in the cable. The system manages this risk with controlled lowering speed, motion compensation, and in many designs, guided travel along rails or a cursor.
4. Releasing or Deploying the Payload
Once the payload sits below the turbulent surface layer, one of two things happens. A free-swimming vehicle such as an AUV detaches and begins its mission. A tethered vehicle such as an ROV stays connected to the vessel through an umbilical or tether, which carries power and data. In a Tether Management System (TMS) setup, the ROV leaves a cage or garage at working depth.
5. Recovering the Payload
Recovery reverses the launch steps, and it is usually harder. The vehicle must be found, captured, and guided back through the splash zone while the vessel keeps moving. The operator lifts the payload clear of the water, brings it onboard, and secures it on deck. A docking head or latching mechanism locks the payload in place so it cannot swing once it is out of the water.
What are the Types of Launch and Recovery Systems?
LARS designs differ by payload, vessel size, sea conditions, and mission length. The right type depends on what you need to deploy and how rough the water gets.
A-frame LARS
An A-frame uses a fixed or pivoting frame on the stern or side of the vessel. The frame holds a sheave or lifting point over the water, and a winch handles the line. It is simple, strong, and widely used for ROVs, towed bodies, and survey gear. Operators pick A-frames for their reliability and straightforward maintenance.
Davit LARS
A davit uses a swinging or pivoting arm to lift loads over the side. It suits smaller vessels and lighter payloads such as rescue boats, AUVs, and small survey tools. Davits take up less deck space than a full A-frame, which makes them practical on compact vessels.
Crane-Based LARS
A knuckle-boom or offshore crane handles heavier or more varied loads. A single crane can launch an ROV one day and move deck cargo the next. That flexibility comes with a trade-off. Cranes need good motion control to manage payload swing, because the load hangs from a long, flexible boom.
Cursor-Type LARS
A cursor system guides the payload along vertical rails through the splash zone. The rails restrict sideways movement, so the payload cannot swing into the hull. This makes cursor systems a strong choice in rough seas and for heavy work-class ROVs.
Active Heave Compensated LARS
These units use sensors and fast hydraulic or electric drives to counter vessel motion. They are common on work-class ROV operations and deepwater campaigns. AHC raises the sea states in which a vessel can launch and recover safely.
TMS-Based LARS
A Tether Management System carries the ROV down inside a cage or garage, then releases it near the work site. The cage protects the vehicle during transit through the water column. The TMS also manages the tether, so the ROV can work without dragging a long cable through currents.
Stern Ramp and Slipway Systems
These let vessels launch and recover boats or unmanned surface vessels by sliding them into and out of the water. Many naval and rescue craft use this method. It avoids lifting the craft entirely, which speeds up operations and reduces risk.
Catahead and Traction-Based Systems
Some designs use a traction winch or tractor curve to handle the lifting line. These systems grip the cable and control tension without storing the full length on a large drum. They reduce the size and weight of the lifting equipment.
Portable and Containerized LARS
These units are built for quick mobilization on vessels of opportunity. They pack into standard shipping containers and can be installed without major vessel modification. They suit short campaigns, charter vessels, and projects where the same equipment must move between ships.
Linear Cable Engines
A linear cable engine uses opposing belts or tires to grip a cable and push or pull it. It handles umbilicals and cables gently, and it can pass connectors and inline bodies. Operators use it for cable deployment and subsea tool handling.
What are the Components of a Launch and Recovery System?
Each part of a LARS has a specific job. Together they form a complete handling chain from the deck to the seabed.
Structural Frame
The A-frame, davit, or crane arm carries the load and sets the outboard reach. Designers size it for the maximum payload, plus dynamic loads from waves and vessel motion. Steel quality, weld design, and fatigue life all matter here.
Winch
The winch spools the lift line or umbilical. Hydraulic winches are common for their power and smooth control. Electric winches are growing in popularity because they offer better efficiency, cleaner operation, and fewer leak risks. The winch size depends on line length, line diameter, and load.
Umbilical or Lift Cable
This cable bears the load. In ROV work, it also carries power and data to the vehicle. Armored umbilicals handle heavy loads and abrasion. Synthetic ropes and lightweight tethers reduce weight and handling effort in some systems.
Power Unit
A hydraulic power unit (HPU) or electric drive supplies energy to the winch and moving parts. The HPU includes a prime mover, pump, reservoir, filters, and coolers. Good cooling and filtration extend component life.
Heave Compensation System
Sensors and control logic keep the payload steady against vessel motion. The system reads vessel movement, then adjusts the winch or a dedicated compensator in real time.
Control Console
The operator uses it to run the system, often from a cabin with direct sight of the deck and water. Good consoles show load, speed, depth, and alarms in a clear layout. Remote controls and handheld units add flexibility during deck work.
Docking Head or Latching Mechanism
This part captures the payload on recovery and locks it firmly in place. A reliable latch prevents the payload from detaching or rotating during lifts.
Guide Rails or Cursor
These reduce payload swing during launch through the splash zone. They give the payload a fixed path and keep it away from the hull.
Tether Management System
On ROV spreads, the TMS stores and releases tether so the vehicle can move freely while the main umbilical stays stable.
Safety Devices
Overload protection, emergency stops, brake systems, and limit switches prevent failures. Many systems use dual or failsafe brakes that engage automatically if power or pressure drops.
Sheaves and Blocks
These redirect the cable smoothly with minimal wear. Correct sheave diameter protects the cable from bending damage.
Deck Mounting and Skid
A skid or base frame spreads the load into the vessel structure. It also allows the system to be installed, removed, or relocated.
Quality components also meet class and regulatory standards. Certifications from bodies such as DNV, ABS, Lloyd’s Register, and Bureau Veritas give owners confidence in design and manufacture. Documented load testing and material traceability support those certifications.
What are the Applications for Launch and Recovery Systems?
LARS serves any industry that needs to put equipment into the water and bring it back safely. The common thread is a valuable payload, a moving vessel, and an unforgiving environment.
Offshore Oil and Gas
Work-class ROVs inspect, maintain, and repair subsea structures, pipelines, manifolds, and wellheads. They also support drilling, completion, and intervention work. A LARS keeps those operations safe and repeatable, even in deep water, high sea state and strong currents.
Offshore Wind
Survey vessels and construction support vessels use LARS to deploy ROVs, sonar systems, and seabed tools around turbine foundations and cable routes. Wind farms need regular inspection of foundations, scour protection, and export cables. Compact and containerized systems fit the smaller vessels that often serve this sector.
Subsea Construction and IMR
Inspection, maintenance, and repair (IMR) campaigns depend on reliable vehicle handling over long periods. A vessel may launch and recover an ROV dozens of times in a single project. Repeatability and low downtime matter more than anything else.
Cable, Pipe, and Umbilical Lay
Installation vessels use cable engines, traction winches, and overboard frames to lay and recover cables, flexible pipes, and umbilicals. These systems control tension so the product is not damaged during installation.
Hydrographic and Geophysical Survey
Survey teams launch towfish, multibeam systems, side-scan sonar, and sensors to map the seabed. Accurate data depends on stable towing and smooth deployment. A good LARS protects expensive sensors and keeps survey lines clean.
Defense and Naval Operations
Navies use LARS for unmanned surface vessels, unmanned underwater vehicles, RHIBs, and mine countermeasure systems. Naval systems often need rapid cycle times, low signature designs, and operation in high sea states.
Scientific Research
Research vessels deploy CTD rosettes, corers, trawls, and deep-sea vehicles to study ocean conditions, marine life, and the seabed. These systems handle a wide range of payloads and often need precise winch control for sampling work.
Search and Rescue
Rescue vessels use davits and slipways to deploy fast rescue crafts in emergencies. Speed and reliability matter because lives depend on the launch.
Salvage and Diving Support
Dive support vessels use LARS for diving bells, basket transfers, and subsea tools. Safety systems in these applications face the strictest requirements, because people travel with the equipment.
Marine Terminals and Ports
Some harbor operations use handling systems for inspection vehicles, mooring equipment, and underwater tools.
What are the Benefits of Launch and Recovery Systems?
A well-matched LARS improves safety, protects assets, and keeps projects on schedule. The gains appear in every phase of an operation, from mobilization to demobilization.
Improved Crew Safety
Controlled handling reduces manual work near moving loads and open water. Fewer people need to stand on the deck during launch and recovery. This lowers the risk of crush injuries, falls, and line strikes.
Asset Protection
Smooth motion and gentle recovery limit damage to expensive vehicles and sensors. A single hard impact can end a mission and cost weeks of repair. A good LARS prevents most of these incidents.
Higher Operating Limits
Heave compensation and guided systems extend the sea states in which work can continue. This cuts weather downtime, which is one of the largest hidden costs in offshore projects.
Faster, Repeatable Operations
Standard procedures and automated functions speed up each cycle. Repeatable launches reduce human error and make planning more reliable.
Lower Operating Cost
Fewer incidents, less downtime, and reduced repair costs improve project economics. Efficient systems also use less fuel and manpower per cycle.
Regulatory Compliance
Certified systems help operators meet class and offshore safety requirements. Documented design and testing make audits and approvals easier.
Greater Flexibility
Modular and containerized units let operators fit different vessels with minimal modification. One system can serve several projects, which improve return on investment.
Reduced Crew Fatigue
Automation lowers the physical and mental load on operators. Rested crews make fewer mistakes.
Lower Vessel Impact
Compact designs reduce deck weight and space use. That leaves more room for other equipment and improves vessel stability.
Better Data and Traceability
Modern controls log loads, cycles, and alarms. Maintenance teams use this data to plan service before failures occur.
What are the Challenges and Limitations of Launch and Recovery Systems?
No system is perfect. Operators should understand the limits before committing to a design, because most problems appear when a system is pushed outside its intended use.
Harsh Sea States
Extreme waves still restrict operations, even with compensation. Every system has a defined maximum sea state, and crews must respect it. Pushing beyond the limit raises the risk of damage and injury.
Snap Loads and Shock
Sudden tension spikes in the cable can damage equipment, shorten cable life, and overload the structure. Good design, correct compensation settings, and proper operating procedure reduce this risk.
Splash Zone Dynamics
Crossing the water surface remains the hardest phase. Waves, currents, and vessel motion all act on the payload at once. Even advanced systems need skilled operators during this stage.
Vessel Integration
Deck space, structural strength, stability, and power supply all affect what can be installed. Retrofits may need engineering studies, stability checks, and class approval. Poor integration can limit how well the system performs.
Weight and Size
Heavier payloads need larger frames and winches. These raise costs and demand more deck area. On smaller vessels, weight and centre of gravity become critical design limits.
Maintenance Demands
Seawater, vibration, and heavy cycling wear down parts. Regular inspection, lubrication, and testing are essential. Hydraulic systems also need clean fluid and leak control. Skipping maintenance shortens equipment life and raises failure risk.
Cable Wear and Fatigue
Repeated bending over sheaves and drums wears cables over time. Operators must track cycles, inspect the cable, and replace it on schedule.
Operator Skill
Even advanced systems depend on trained crews. Poor technique can negate the benefits of good equipment. Training, clear procedures, and regular drills keep performance high.
High Upfront Cost
Advanced AHC and custom-engineered systems carry a significant price. Rental or containerized options can ease this, especially for short projects.
Regulatory Complexity
Standards vary by region and class society. Operators must plan certification early to avoid delays at mobilization.
Power and Environmental Limits
Hydraulic systems risk oil leaks, which matter in sensitive waters. Operators may need environmentally acceptable lubricants, leak containment, or electric alternatives.
How to Choose the Right Launch and Recovery System?
The right choice depends on matching the system to the job, the vessel, and the environment. Work through these factors in order, and write down the answers before you talk to suppliers.
1. Define the payload
Note its weight, dimensions, shape, and type. An ROV, an AUV, and a rescue boat each need a different handling approach. Include accessories such as a TMS, tooling, or sensors in the total weight. Add a safety margin for dynamic loads.
2. Set the operating conditions
Identify the expected sea states, water depth, and current. Estimate how often you will launch and recover. Rough environments call for AHC or cursor systems. Calm, shallow work may need only a simple A-frame and winch.
3. Check the vessel
Review deck space, available power, stability limits, and mounting points. Confirm the vessel can carry the added weight and that the structure can take the loads. Check whether the system will use ship power or its own HPU.
4. Choose the lifting configuration
Pick an A-frame, davit, crane, cursor, or catahead design based on reach, capacity, and motion control needs. Consider where on the vessel the system will sit, because stern, side, and moonpool installations behave differently.
5. Match the cable and winch
Select the umbilical, rope, or wire for strength, weight, and handling. Choose between drum winches, traction winches, and linear engines based on line length and tension control needs.
6. Confirm safety and certification
Look for compliance with DNV, ABS, Lloyd’s Register, or Bureau Veritas rules, plus load testing and documented safety functions. Ask about failsafe brakes, emergency recovery, and overload protection. Safety features should work even if power fails.
7. Consider automation and controls
Modern control systems can include remote operation, data logging, and diagnostics that improve efficiency. A clear operator interface reduces errors during tense moments.
8. Plan for mobilization
Decide whether you need a permanent installation or a portable unit. Containerized systems cut installation time and suit vessels of opportunity. Permanent systems may suit long-term vessels better.
9. Plan for maintenance and support
Ask about spare parts, service networks, training, and response times. A system is only as reliable as the support behind it.
10. Compare lifecycle cost
Look beyond purchase price. Include installation, maintenance, downtime risk, energy use, and resale value. A cheaper system that fails often costs more in the end.
11. Evaluate the manufacturer
Choose a supplier with proven offshore experience, strong engineering capability, and references from similar projects. Ask for case studies, factory acceptance tests, and a clear commissioning plan.
A custom-engineered system often delivers the best fit for complex operations. Standard or containerized units can work well for shorter campaigns and varied vessels. Either way, early engineering input helps you avoid costly changes later.
Reliable Launch & Recovery Systems for Demanding Offshore Operations
Offshore work leaves little room for error. The right LARS gives your team control, protects valuable assets, and keeps projects moving through changing conditions. At Reel Power Marine & Energy, we design and manufacture launch and recovery systems for subsea, ROV, and umbilical deployment. Our headquarters in Houston, Texas, houses the engineering and manufacturing that stand behind every unit we deliver.
Our LARS range covers the full handling chain:
Containerized ROV deployment system
We built this modular unit to deploy work-class ROVs, other underwater craft, and subsea tools using a non-armored tether. It lowers weight and mobilization costs, speeds up deployment, and fits a wide range of vessels of opportunity.
Traction winches
Our winches hold back and control tension on wire rope, ROV cable, synthetic rope, and wireline. You get precise tension management where safe cable handling matters most.
Linear cable engines
Our tire-drive design is gentle on cables and umbilicals, which limits stress and wear. The system passes connectors and subsea bodies while keeping tension consistent.
Custom A-frames and overboard frames
We design these around your application, with capacities up to 60,000 lbs. We power them with our own hydraulic power units or with ship power, and DNV certification is available.
